Tuesday, April 21, 2009

Air-conditioning and Global Warming

Consider this thought experiment:

You move a refrigerator into a room. The door of the fridge is left opened, but the door and the windows of the room are all closed. The fridge is powered on. One hour later you enter the room. Will the room be cooler or warmer?

Some of you have studied thermodynamics in school. The Second Law of Thermodynamics dictates that, in the thought experiment just mentioned, the room will be warmer. The refrigerator cannot take away more heat than it generates.

Air-conditioner works in the same principle as a fridge, except that the heat is channeled out of the room. So, while the room is cooled, the earth gets warmer each day (assuming that the earth cannot dissipate heat fast enough).

Unfortunately, air-conditioner, like air travel, is “necessary evil”. Lee Kuan Yew, former prime minister of Singapore, hailed air-con as human’s greatest invention. Without air-conditioner, workers in tropical countries get tired fast, and we cannot possibly match the productivity of our counterparts in temperate regions.

Still, there is something we can do. Refer to my other post – Cool Biz – for more details.

In Asia, many hotels have installed a ‘main switch’ for each of their rooms. Hotel clients are required to insert their keys into a ‘power slot’ in order to turn on the switch. When they leave their rooms, they take out their keys and the air-con, lights and TV will be switched off automatically. This is an energy saving measure.

Somehow, Asians are so ‘smart’ that they have devised ways to cheat the energy saving system, e.g. by inserting a piece of paper into the main switch. Thus, they could leave the air-conditioners on when nobody is in the room.

For the sake of our Mother Earth, please do not do so…

Related posts:
Beyond Earth Hour
Cool Biz
Air Travel & Global Warming


  1. Nowadays so hot, and Malaysia not only hot but humid, how to survive without air con? It's one of the best invention of mankind! Yes, it's definitely a necessary evil! The most I can do is switch off the air con when I don't need it : )

  2. I try not to use air-con too much (believe me or not, Canada is crazy humid and hot in the summer!) because it's so expensive to run. Yet; it is necessary sometimes...

    I find people overuse it though. We I worked in Hong Kong, it was freewing cold in most offices!

  3. Beating the system at the Earth's expense. For them, the end justifies the means. Sigh.

  4. Oh yes, aircon is a must in Malaysia... without aircon I can't imagine how I could sleep at night. The most is I put the temperature at 26 with sleep mode on.

  5. foongpc, neoYes, what you do are right.

    zhuI have a feeling that Asians are more attached to air-con.

    happysurferThis is called short-sightedness!

  6. I hate air-con but my bf loves it.. :/

  7. 没有冷气我肯定完蛋。环球升温是个老问题,大家知道不好,可是不用冷气却没几个人能办得到。

  8. THBIf you bf strip like you do, then no need air-con lah... ;)


  9. Oops, I was one of those who inserted the card in to "cheat" the system.

    I just wanted my refrigerator to work. My Haagen Dazs ice cream will melt. =(

  10. I'm thinking about installing one in my home too. Because recently the heat is simply unbearable! :(

  11. yes my freind you are absoutely right we need to conserve conventional source of energy in order to protect our earth just for the sake of little comfrt we are putting or next generation in great hazards situation,while my opinion is that we should avoid the use of power consuming appliance as minimum as possible.while the more we are running towards comfort the more we are making our self sensitive & weak.

  12. Wow! I just though of this same thing also! I started taking an HVAC class. The answer is population control. Each human gives off 300BTUs.

    Human procreation will be its demise. Ironic.

  13. Air-conditioner works in the same principle as a fridge, except that the heat is channeled out of the room. So, while the room is cooled, the earth gets warmer each day.

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  14. Hi, i have recently tried to find out the heat efficiency of air cons, however i can find nothing on this only energy efficiency. Surely some sort of change of regulations regarding statuatory provision of heat efficiency would help at least improve the destructive effect these things do.

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